2020-11-24 Indy DID Method Specification Call

Owned by Stephen Curran
Last updated: Dec 01, 2020 by Markus Sabadello
3 min read

Summary

  • Discovery of networks
    • Given a DID, how to find it's network via gossiped ledger data
  • Versioning

Recording from the call: 20201124 Indy DID Method Specification Call Recording

Hyperledger is committed to creating a safe and welcoming

community for all. For more information

please visit the Hyperledger Code of Conduct.

Welcome and Introductions

Announcements

  • TBD

Attendees

Collaboration Channels

Previous Discussion:

  • The specific will be specific that all DIDs MUST be self-certifying – e.g. derived from the initial public key used in the NYM
  • We'll use ":" for subsidiary ledgers, and we'll include placeholder support for KERI, leading to 4 cases:
    • Ledger with no subsidiary name, example: did:indy:sovrin:12345
    • KERI identifier on a ledger with no subsidiary name, example: did:indy:sovrin:keri:12345
    • Ledger with subsidiary name, example: did:indy:sovrin:staging:keri:12345
    • KERI identifier on a ledger with a subsidiary name, example: did:indy:sovrin:staging:keri:12345
  • To find networks we will require at least the first and perhaps the second of these approaches, while the rest are suggested:
    • Config files for one or more known networks
    • A mechanism for a ledger operator to register discovery information for other ledgers (aka "human gossip")
    • Decentralized registries based on verifiable credentials
    • Other registry mechanisms, such as the DDNR proposal

Online Discussion (from RocketChat this week)


Discussion:

  • Discussion led by Daniel Hardman about how to implement the gossiping mechanism via "networks" ledger DIDs -
  • How to find config files in a centralized place?
    • ToIP, DIF, OrgBook for networks
    • Folder where the spec is – indy-did-method repo
  • How to find previous versions of DIDs and what are the implementation ramifications of that?
    • <did>?version-id=<txnid>
      • Return the txnid as part of DID resolution so it can be included in URIs
    • <did>?version-time=<timestamp>
      • Indy does do timestamping - coarse:
        • tracked as part of consensus to (a) within 5 minutes (b) batch time greater than the last one
        • leader node picks, but vetted by other nodes, understanding that the leader node's time could drift.
      • How to do time based querying?
        • Probably not indexed
        • Could do binary search querying of the txnids
      • Code needs to be written to do this.


Summary - Cross-Registering Networks on a Ledger

  • Start with a config file for one or more networks
    • The config file will contain at least the pool transactions for the ledger – could contain more; see below
  • On the ledger will be one or more DIDs that have associated "Network Metadata" information that includes (and might be limited to) information about cross-registered networks.
    • Proposed options for finding the "Network Metadata DID(s)" with the network listings:
      • A "network metadata" DID embedded in the config file.
        • Proposed that writing to the DID would be controlled, such as by a Trustee or some other config rules.
      • Could be found via resolving "known DIDs" so that knowledge of the "special" DID is not needed:
        • DIDs of each Trustee on the network (requires search by role)
        • DIDs of each Steward on the network (requires search by role)
        • A DID with a new "Network Metadata" role (requires search by role)
          • Same as putting the DID in the config file, but this enables finding it by role.
        • Resolving the "namespace DID" (e.g. DID with no ledger specific identifier). Requires change to DID Core Spec.
    • Decision: DID in Config File, Trustee DID, Steward DID, New Role DID, Namespace DID
      • Impact: What code needs to be written?
      • Impact: If trustee or steward DIDs – what processing rules should be applied?
  • Decision: Does the network metadata go into an ATTRIB, or does it go into the DIDDoc associated with the DID?
  • Data associated with the "Network Metadata" DID(s):
    • For cross-registered networks, an array:
      • Namespace
      • Pool Transactions file contents or
      • Location of Pool Transactions file
    • Metadata about the ledger
      • Link to Governance Framework information
      • Other?
    • Decision: What categories of data should go into a DID holding Network Metadata?
    • Decision: What is the exact format of the data?
  • Centralized publishing of ledger config files
    • All the publishing of ledger config files in a known place – e.g. github – and under the control of an entity such as Hyperledger or DIF
      • This is centralized control because the maintainers accept the PRs that update the data
    • Decision: Do we want to propose a location to publish config files?
    • If yes, Decision: Where?